SOLUTION: if a plane is travelling 3100 km at 790km/h and then encounters a tailwind that boosts its speed tp 990km/h for the next 2800km. what was the total time for the trip?what was teh a

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Question 63665: if a plane is travelling 3100 km at 790km/h and then encounters a tailwind that boosts its speed tp 990km/h for the next 2800km. what was the total time for the trip?what was teh average speed of the plane for this trip?
Answer by ptaylor(2198) About Me  (Show Source):
You can put this solution on YOUR website!
The plane travels 3100 km (d1) at 790 km/h (r1) and 2800 km (d2) at 990km/hr (r2)
Let t1=time it takes the plane to travel 3100km @790km/hr
and t2=time it takes the plane to travel 2800km @990km/hr
We'll use the formula:
distance=(rate)(time) or d=rt
t1=d1/r1 =(3100 km)/(790km/hr)=3.92 hrs and
t2=d2/r2 =(2800 km)/(990km/hr)=2.83 hrs
Total time for the trip =t1+t2=2.83 hrs+3.92 hrs =6.75 hrs
average rate = (total distance)/(total time)
total distance =5900 km
total time=6.75 hrs

average rate=5900/6.75=874.1 km/hr
ck
d=rt
5900 km=(874.1km/hr)(6.75 hr)
5900 km =5900 km
Hope this helps. Happy holidays---ptaylor